We propose to study the metabolism of cervical connective tissue in the relation to its changing function in pregnancy and labor. We will quantitate the changing mucopolysaccharide composition of the cervical stroma in pregnancy and investigate the structure of cervical proteoglycan in both non-pregnant and parturient state. The rate of hyaluronic acid synthesis and quantitation of its synthesizing enzymes will be determined. We will relate these biochemical determinations to histological and ultrastructure studies of the cervix. Estrogen, progesterone and corticosteroid tissue concentrations and the concentrations of these receptor proteins will be determined and related to the biochemical and histologic studies. Studies will be performed in rat and sheep models and in human biopsy specimens from normal non-pregnant, term pregnant, and puerperal patients and from patients with abnormal cervical function.